As shown in FIG. 10, a conventional fluidized bed waste incinerator comprises: a combustion chamber 2 and a freeboard space 3 formed in a main furnace unit 1; a waste inlet 4 formed in the front wall 1a of the main furnace unit 1; an ash discharge outlet 6 formed in the rear base portion of the main furnace unit 1; a discharging device 5 provided at this ash discharge outlet 6, which discharges incinerated ash and incombustible material whilst leaving the fluid medium S; and a plurality of dispersive air pipes 7 arranged mutually in parallel passing through the lower portion of the combustion chamber in a horizontal direction.
In the composition described above, the heated fluid medium S is caused to become fluid by means of dispersive air injected into the fluid medium S in the furnace main unit 1 from dispersive air pipes 7. Waste to be incinerated is introduced via the waste inlet 4 and mixes into the fluid medium S, and the waste is heated, fluidized and then combusts in a combustion zone in the upper portion of the combustion chamber 2. Incinerated ash is carried to the ash discharge outlet 6 by the downward movement of the fluid medium S, and then discharged.
The dispersive air pipes 7 pass through side walls 1b of the main furnace unit 1 transversely in a horizontal direction. Adjacent dispersive air pipes 7 are spaced to have a gap of approximately 100-150 mm between each other. There are cases where large items of incombustible material or linear items of incombustible material, such as wire or the like, which are larger than this gap, may be present in the waste introduced into the incinerator, or large lumps of clinker may form during incineration. In these cases, there arises a problem that such items will accumulate above the dispersive air pipes 7, due to the narrow gaps between the dispersive air pipes, and will not be discharged from the ash discharge outlet 6, thereby rendering the incinerator inoperable.